Is a waqf suspended until death valid, and is it considered a will to the heirs? And is the bequeathed quarter combined with the one-third if it is executed as a will? And is the supervisor entitled to consider the circumstances of the heirs when executing this will/waqf?

A conditional endowment that takes effect upon death is valid according to the majority of jurists. It is treated as a bequest, and thus is calculated from one-third of the inheritance, unless the heirs permit an increase. If the endower stipulates the endowment for his children, the children of daughters are not included, according to the majority of jurists, unless the endower explicitly states their inclusion. It is advisable to refer to the Sharia (definition) court to properly establish and execute the endowment.